LAMMPS (12 Jun 2025 - Development - patch_12Jun2025-739-g2644e7f6fa-modified)
  using 1 OpenMP thread(s) per MPI task

units		real
atom_style	full

read_data	data.spce
Reading data file ...
  orthogonal box = (0.02645 0.02645 0.02641) to (35.5328 35.5328 35.4736)
  2 by 2 by 1 MPI processor grid
  reading atoms ...
  4500 atoms
  scanning bonds ...
  2 = max bonds/atom
  scanning angles ...
  1 = max angles/atom
  orthogonal box = (0.02645 0.02645 0.02641) to (35.5328 35.5328 35.4736)
  2 by 2 by 1 MPI processor grid
  reading bonds ...
  3000 bonds
  reading angles ...
  1500 angles
Finding 1-2 1-3 1-4 neighbors ...
  special bond factors lj:    0        0        0       
  special bond factors coul:  0        0        0       
     2 = max # of 1-2 neighbors
     1 = max # of 1-3 neighbors
     1 = max # of 1-4 neighbors
     2 = max # of special neighbors
  special bonds CPU = 0.000 seconds
  read_data CPU = 0.015 seconds

pair_style	lj/cut/coul/long 12.0 12.0
kspace_style	pppm 1.0e-4

pair_coeff	1 1 0.15535 3.166
pair_coeff	* 2 0.0000 0.0000

bond_style	harmonic
angle_style	harmonic
dihedral_style	none
improper_style	none

bond_coeff	1 1000.00 1.000
angle_coeff	1 100.0 109.47

special_bonds   lj/coul 0.0 0.0 1.0
Finding 1-2 1-3 1-4 neighbors ...
  special bond factors lj:    0        0        1       
  special bond factors coul:  0        0        1       
     2 = max # of 1-2 neighbors
     1 = max # of 1-3 neighbors
     2 = max # of special neighbors
  special bonds CPU = 0.000 seconds

neighbor        2.0 bin

fix		1 all shake 0.0001 20 0 b 1 a 1
Finding SHAKE clusters ...
       0 = # of size 2 clusters
       0 = # of size 3 clusters
       0 = # of size 4 clusters
    1500 = # of frozen angles
  find clusters CPU = 0.000 seconds
fix		2 all nvt temp 300.0 300.0 100.0

# make certain that shake constraints are satisfied
run 0 post no
PPPM initialization ...
  using 12-bit tables for long-range coulomb
  G vector (1/distance) = 0.21848247
  grid = 15 15 15
  stencil order = 5
  estimated absolute RMS force accuracy = 0.031943453
  estimated relative force accuracy = 9.619676e-05
  using double precision FFTW3
  3d grid and FFT values/proc = 3380 960
Generated 0 of 1 mixed pair_coeff terms from geometric mixing rule
Neighbor list info ...
  update: every = 1 steps, delay = 0 steps, check = yes
  max neighbors/atom: 2000, page size: 100000
  master list distance cutoff = 14
  ghost atom cutoff = 14
  binsize = 7, bins = 6 6 6
  1 neighbor lists, perpetual/occasional/extra = 1 0 0
  (1) pair lj/cut/coul/long, perpetual
      attributes: half, newton on
      pair build: half/bin/newton
      stencil: half/bin/3d
      bin: standard
Per MPI rank memory allocation (min/avg/max) = 10.94 | 10.95 | 10.96 Mbytes
   Step          Temp          E_pair         E_mol          TotEng         Press     
         0   0             -16692.358      0             -16692.358     -1289.8319    
Loop time of 1.215e-06 on 4 procs for 0 steps with 4500 atoms


group		one molecule 1 2
6 atoms in group one

# the following section shows equivalences between using the force/tally compute and other computes and thermo keywords

# compute pairwise force between two molecules and everybody
compute		fpa one group/group all pair yes kspace no boundary no
# tally pairwise force between two molecules and the all molecules
compute		c1 one force/tally all
# tally the force of all with all (should be zero)
compute		c2 all force/tally all
# collect per atom data. only reduce over the first group.
compute		one one reduce sum c_c1[1] c_c1[2] c_c1[3]
compute		red all reduce sum c_c2[1] c_c2[2] c_c2[3]
# determine magnitude of force
variable	fpa equal sqrt(c_fpa[1]*c_fpa[1]+c_fpa[2]*c_fpa[2]+c_fpa[3]*c_fpa[3])
variable	for equal sqrt(c_one[1]*c_one[1]+c_one[2]*c_one[2]+c_one[3]*c_one[3])
# round to 10**-10 absolute precision.
variable	ref equal round(1e10*sqrt(c_red[1]*c_red[1]+c_red[2]*c_red[2]+c_red[3]*c_red[3]))*1e-10
variable	all equal round(1e10*c_c2)*1e-10

velocity	all create 300 432567 dist uniform

timestep	2.0

# v_fpa and v_for and c_c1, c_fpa[] and c_one[] should all each have the same value. v_ref and c_c2 should be zero
thermo_style    custom step v_fpa v_for c_c1 c_fpa[1] c_one[1] c_fpa[2] c_one[2] c_fpa[3] c_one[3] v_ref v_all
thermo		10

run 50
PPPM initialization ...
  using 12-bit tables for long-range coulomb
  G vector (1/distance) = 0.21848247
  grid = 15 15 15
  stencil order = 5
  estimated absolute RMS force accuracy = 0.031943453
  estimated relative force accuracy = 9.619676e-05
  using double precision FFTW3
  3d grid and FFT values/proc = 3380 960
Generated 0 of 1 mixed pair_coeff terms from geometric mixing rule
WARNING: Compute force/tally only called from pair style (src/TALLY/compute_force_tally.cpp:78)
WARNING: Compute force/tally only called from pair style (src/TALLY/compute_force_tally.cpp:78)
Neighbor list info ...
  update: every = 1 steps, delay = 0 steps, check = yes
  max neighbors/atom: 2000, page size: 100000
  master list distance cutoff = 14
  ghost atom cutoff = 14
  binsize = 7, bins = 6 6 6
  2 neighbor lists, perpetual/occasional/extra = 1 1 0
  (1) pair lj/cut/coul/long, perpetual
      attributes: half, newton on
      pair build: half/bin/newton
      stencil: half/bin/3d
      bin: standard
  (2) compute group/group, occasional, copy from (1)
      attributes: half, newton on
      pair build: copy
      stencil: none
      bin: none
Per MPI rank memory allocation (min/avg/max) = 11.69 | 11.7 | 11.71 Mbytes
   Step         v_fpa          v_for           c_c1         c_fpa[1]       c_one[1]       c_fpa[2]       c_one[2]       c_fpa[3]       c_one[3]        v_ref          v_all     
         0   22.7331        22.7331        22.7331       -17.068297     -17.068297     -8.8348326     -8.8348325     -12.141367     -12.141367      0              0            
        10   11.736904      11.736904      11.736904     -3.3896996     -3.3896996      9.1193917      9.1193917     -6.5651776     -6.5651776      0              0            
        20   5.6120316      5.6120316      5.6120316     -0.60046831    -0.60046831    -4.4481268     -4.4481268      3.3687541      3.3687541      0              0            
        30   17.292609      17.292609      17.292609      6.1793031      6.1793031     -10.593981     -10.593981      12.190903      12.190903      0              0            
        40   18.664432      18.664432      18.664432      5.4727799      5.4727799     -6.9329308     -6.9329308      16.442146      16.442146      0              0            
        50   12.130401      12.130401      12.130401     -1.0321245     -1.0321245      8.0035536      8.0035536     -9.0567363     -9.0567363      0              0            
Loop time of 0.376488 on 4 procs for 50 steps with 4500 atoms

Performance: 22.949 ns/day, 1.046 hours/ns, 132.806 timesteps/s, 597.629 katom-step/s
99.4% CPU use with 4 MPI tasks x 1 OpenMP threads

MPI task timing breakdown:
Section |  min time  |  avg time  |  max time  |%varavg| %total
---------------------------------------------------------------
Pair    | 0.29263    | 0.29983    | 0.30907    |   1.1 | 79.64
Bond    | 2.6989e-05 | 3.2437e-05 | 4.5538e-05 |   0.0 |  0.01
Kspace  | 0.02192    | 0.03101    | 0.038325   |   3.3 |  8.24
Neigh   | 0.031273   | 0.03129    | 0.03131    |   0.0 |  8.31
Comm    | 0.004391   | 0.004525   | 0.0047061  |   0.2 |  1.20
Output  | 0.0035009  | 0.00351    | 0.0035348  |   0.0 |  0.93
Modify  | 0.0056161  | 0.005627   | 0.0056342  |   0.0 |  1.49
Other   |            | 0.0006593  |            |       |  0.18

Nlocal:           1125 ave        1148 max        1097 min
Histogram: 1 0 0 1 0 0 0 0 1 1
Nghost:        12212.5 ave       12269 max       12162 min
Histogram: 1 0 0 1 0 1 0 0 0 1
Neighs:         650496 ave      675112 max      631353 min
Histogram: 1 0 0 1 1 0 0 0 0 1

Total # of neighbors = 2601983
Ave neighs/atom = 578.21844
Ave special neighs/atom = 2
Neighbor list builds = 4
Dangerous builds = 0

Total wall time: 0:00:00
